STJ: set initial capacity of JsonObject if known (#96417) (#96486)

* STJ: set initial capacity of JsonObject if known (#96417) * fix nullable type typo * just tweaking to run the gh actions again to confirm * wip/squash. use `TryGetNonEnumeratedCount`/polyfill * wip. go back to using just a check against ICollection * wip/squash. remove System.Linq dependency * wip. avoid adding a new field * wip/squash. move more of the logic into the ctor * wip/squash. use static private helper method * wip/squash. use null-coalescing operator also, caught one more spot to use the IsCaseInsensitive helper * wip/squash. use more syntax sugar! --------- Co-authored-by: Eirik Tsarpalis <[email protected]>
dotnet · Jan 10, 2024 · 1303c3a · 1303c3a
1 parent 813ff97
commit 1303c3a
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Showing 2 changed files with 17 additions and 5 deletions.
diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonObject.IDictionary.cs b/src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonObject.IDictionary.cs
@@ -199,8 +199,8 @@ public bool Remove(string propertyName)
 
             if (dictionary is null)
             {
-                bool caseInsensitive = Options.HasValue ? Options.Value.PropertyNameCaseInsensitive : false;
-                dictionary = new JsonPropertyDictionary<JsonNode?>(caseInsensitive);
+                dictionary = new JsonPropertyDictionary<JsonNode?>(IsCaseInsensitive(Options));
+
                 if (jsonElement.HasValue)
                 {
                     foreach (JsonProperty jElementProperty in jsonElement.Value.EnumerateObject())
@@ -224,6 +224,9 @@ public bool Remove(string propertyName)
             return dictionary;
         }
 
+        private static bool IsCaseInsensitive(JsonNodeOptions? options) =>
+            options?.PropertyNameCaseInsensitive ?? false;
+
         /// <summary>
         /// Provides a coherent view of the underlying representation of the current node.
         /// The jsonElement value should be consumed if and only if dictionary value is null.

diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonObject.cs b/src/libraries/System.Text.Json/src/System/Text/Json/Nodes/JsonObject.cs
@@ -33,10 +33,19 @@ public JsonObject(JsonNodeOptions? options = null) : base(options) { }
         /// <param name="options">Options to control the behavior.</param>
         public JsonObject(IEnumerable<KeyValuePair<string, JsonNode?>> properties, JsonNodeOptions? options = null) : this(options)
         {
+            bool isCaseInsensitive = IsCaseInsensitive(options);
+
+            JsonPropertyDictionary<JsonNode?> dictionary = properties is ICollection<KeyValuePair<string, JsonNode?>> propertiesCollection
+                ? new(isCaseInsensitive, propertiesCollection.Count)
+                : new(isCaseInsensitive);
+
             foreach (KeyValuePair<string, JsonNode?> node in properties)
             {
-                Add(node.Key, node.Value);
+                dictionary.Add(node.Key, node.Value);
+                node.Value?.AssignParent(this);
             }
+
+            _dictionary = dictionary;
         }
 
         /// <summary>
@@ -67,7 +76,7 @@ internal JsonObject(JsonElement element, JsonNodeOptions? options = null) : this
         /// <summary>
         /// Gets or creates the underlying dictionary containing the properties of the object.
         /// </summary>
-        internal JsonPropertyDictionary<JsonNode?> Dictionary => _dictionary is { } dictionary ? dictionary : InitializeDictionary();
+        internal JsonPropertyDictionary<JsonNode?> Dictionary => _dictionary ?? InitializeDictionary();
 
         internal override JsonNode DeepCloneCore()
         {
@@ -80,7 +89,7 @@ internal override JsonNode DeepCloneCore()
                     : new JsonObject(Options);
             }
 
-            bool caseInsensitive = Options.HasValue ? Options.Value.PropertyNameCaseInsensitive : false;
+            bool caseInsensitive = IsCaseInsensitive(Options);
             var jObject = new JsonObject(Options)
             {
                 _dictionary = new JsonPropertyDictionary<JsonNode?>(caseInsensitive, dictionary.Count)